1. Field of the Invention
This invention relates to a magnetic tape magazine, and more particularly to a magnetic tape magazine which contains a magnetic recording tape wound on a tape feed-out core and a tape take-up core or on a single feed-out and take-up core provided therein.
2. Description of the Prior Art
In order to minimize the size of magnetic tape recorders, it is necessary to make the size of the magnetic tape magazine used therein as small as possible. In order to reduce the size of the magnetic tape magazine, it is necessary to manufacture thin long-play magnetic tapes. The long-play magnetic tapes should best be mirror finished to carry thereon a magnetic recording material with high density. The mirror finished thin magnetic tape is apt to jam and is hard to wind up on a core so that the side faces of the coiled tape are perfectly flat. For instance, the side faces of the tape convolution are apt to be curved or rough. This is because the friction coefficient between the recording face of the tape and a backing member located in contact therewith is as large as 0.4 or more and because an air flow sometimes forms a space or air gap between the tape and the backing member. Trouble in the tape feed occurs frequently when the speed of the tape feed increases.
In the conventional magnetic tape magazine, a pair of friction sheets are inserted between the tape convolution and the upper and lower walls of the magazine to make the side faces of the tape convolution flat and smooth. However, it is very difficult to wind the tape on the core with consistent smoothness. Particularly, when the tape is quickly advanced in the magazine or rewound at a high speed, the side faces of the tape convolution become rough and the side edges of the tape rub the inner face of the walls or the friction sheets so that back tension on the tape increases when the tape is advanced in playing or recording.
Because of the increased back tension on the tape, the edges of the tape are permanently deformed and the recorded signal carried on the tape is degraded in quality and accordingly the quality of reproduction is lowered.
The present invention is concerned with various types of tape magazines having two cores or hubs without a flange.